Optic Neuritis: An Update. II. Optic Neuritis and Multiple Sclerosis

Abstract

Demyelinating optic neuritis (DON) is an acute inflammatory demyelinating disorder affecting the optic nerve. The risk of having a subsequent clinical episode elsewhere in the central nervous system leading to a diagnosis of clinically definite multiple sclerosis (CDMS) varies in different parts of the world. In countries with a high prevalence of MS, most patients with DON will eventually develop CDMS. The presence of oligoclonal bands in cerebrospinal fluid and asymptomatic lesions on magnetic resonance imaging (MRI) of the brain at presentation are strong predictors of progression to CDMS. The Optic Neuritis Treatment Trial reported that DON patients treated with intravenous methylprednisolone had a delay in progression to CDMS, but only up to two years. Interferon-β and glatiramer actetate have now been shown to reduce the risk of developing CDMS after two to three years when compared with placebo. The BENEFIT study has demonstrated that delaying interferon-β1b therapy in patients presenting with a clinically isolated syndrome (CIS) such as optic neuritis leads to a slightly higher risk for sustained disability progression compared with patients who started interferon-β1b after a CIS. Controversy remains if these small benefits of reducing conversion to CDMS from CIS and slowing disability with interferon-β treatment outweigh the adverse effects of the medication and its costs as the overall disability progression off treatment is mild, at least in the short-term, and particularly in patients in whom optic neuritis is the initial event.

Keywords:

• Optic neuritis
• multiple sclerosis
• magnetic resonance imaging
• interferon-β
• glatiramer acetate